Tag: NASA

The Planetary Society says humans orbiting Mars is important before they land on it

On Thursday night (IST), the Planetary Society announced the results of a workshop it hosted earlier this week to re-engage with the future of human spaceflight. The advocacy group concluded that humans orbiting Mars was a crucial step before humans could land on Mars.

The workshop, called “Humans Orbiting Mars”, was held with officials from the aerospace industry, scientific community and NASA in attendance. They addressed the question of whether human spaceflight to Mars by 2033 was feasible if NASA’s budget increased only by 2-3% between now and then (to keep up with inflation), and assuming the agency’s contribution to the International Space Station would end by 2024. The answer was ‘Yes’ conditional to the orbit-first-land-next strategy.

Some results from the workshop were made public by Scott Hubbard, former director of the NASA Ames Research Center, and John Logsdon, founder of the Space Policy Institute at George Washington University, in a presser. The Society’s president and popular science communicator Bill Nye also presented some tidbits, but none of them were forthcoming about the precise details of the Society’s strategy.

Hubbard said that having humans orbit Mars first before landing was important to break “this very challenging effort into smaller, more executable pieces”, differentiating it from some private sector approaches to the red planet that Logsdon said “exist but don’t seem credible”. They admitted they were conscious of the strategy’s parallels to the Apollo 8 mission, which invigorated public interest in space exploration by carrying the first humans into an orbit around the moon in 1968 and giving humanity its first view of Earthrise.

A notional timeline for the 2033 mission was presented also, with crewed test-flights in cislunar orbits being planned for 2025 and 2027. Mars missions are fixed to launch windows every 26 months to coincide with the planet’s opposition, when it comes closest to Earth. However, the launch window in 2033 provides a suitable focus year also because NASA hopes to have tested the necessary spaceflight technologies and experience through its Asteroid Retrieval Mission in the 2020s.

The Society’s space-policy writer Casey Dreier concluded on his blog:

Over the next few months, we will work to publish as much of the content presented at the workshop as we can. And later this year, we will release a report based on the discussions and feedback from this meeting formalizing our thoughts and ideas on this path forward.

However, the presser only left reporters with more questions than answers. It may have been wiser to announce all the results of the workshop alongside the report instead of releasing vague details now, even if it appears the Planetary Society has a detailed architecture of the concept in place.

And – as if to have the Society reconsider its barb about infeasible private missions to Mars – the report’s release later this year could coincide with SpaceX’s much-awaited announcement of the details of its Mars Colonial Transporter, a transport vehicle that CEO-CTO Elon Musk has promised will be very different from the Dragon and Falcon 9 rockets it currently operates. Musk is also expected to announce new spacesuit designs meeting utility requirements by the end of 2015.

Featured image credit: NASA

NASA readies to test history’s largest, most powerful booster for its new rocket

NASA’s massive heavy-lift rocket, the Space Launch System, which will one day ferry humans to deep-space destinations and back, has become notorious for the scale of engineering backing it. In September 2014, agency administrator Charles Bolden had unveiled the world’s largest welder to mark the start of the SLS’s construction. Next, on March 11, NASA will test history’s largest and most powerful booster that will power the SLS.

The booster has five stages, and has been adapted from the four-stage version used for the Space Shuttle program. It is 47 meters in length, 3.6 meters in diameter, and weighs 801 tons. The test-fire will be conducted by prime contractor Orbital ATK at its T-97 test stand in Promontory, Utah, at 11.30 am EDT (9 pm IST) on Wednesday.

Even though the booster’s components have been verified in the past, the addition of the extra stage makes it a new configuration that engineers must test for once more.  Wednesday’s test, in this context, will be for the full duration – two minutes – for which it will be expected to fire on launch day, although it will be laid horizontally on a test-bed (like in the video below).

The maximum thrust it produces will be about 16 million newtons, burning 5,500 kg of solid propellant per second. On the SLS itself, two such boosters will join four RS-25 engines to generate a combined thrust of 37.3 million newtons. (To compare, an Airbus A380-800 uses four Rolls-Royce Trent engines to generate a combined thrust of 0.96 to 1.68 million newtons to fly.)

Here’s a video from 2009 showing how one of these tests goes (Don’t miss it when the commentator says, “Amazing display of power” at 1:36).

https://www.youtube.com/watch?v=J2UDTNEPr0Y

A second test will happen in March 2016. This month’s test will qualify the booster for operation at 32 degrees Celsius, the one next year will qualify it for performance at 4 degrees Celsius. The disparate temperatures mimic the two which the booster will be expected to perform in: during launch and in space. If both tests are successful, it will finally have to pass a design certification review in the last third of 2016 to finally qualify for use.

The idea for the SLS was born from NASA’s desire to cope with its Constellation Program starting to crumble in 2009, when President Barack Obama cancelled all deep-space exploration efforts. In efforts to ensure its $9-billion investment remained fruitful, the agency conceived of the SLS, with a new rocket at its heart. A lot of hope also underscores this new commitment: plans for a booster-test date back to 2012, while engineers conducted three test-firings of the booster between 2009 and 2011 during development for the Constellation Program’s Ares rocket.

The multipurpose module on-board the rocket which will hold humans is called Orion, which the rocket has been designed around. The first test flight when both Orion and SLS will fly together has been planned for November 2018, when they will undertake a three-week long trip through an orbit just beyond the moon and return to Earth. Orion’s own inaugural (unmanned) mission was successfully completed in December 2014, with a Delta IV heavy rocket.

NASA plans for the SLS-Orion to be able to get humans to Mars in the 2030s. To get farther – such as to the asteroids between Mars and Jupiter – the agency plans to gradually step up booster capabilities. The 2018 test will lift 70 tons, with a rocket 64.6 meters tall and 8.4 meters wide.

rockets

Current projections place the ultimate goal at a lift capability of 130 tons into low-Earth orbit – the heaviest ever. The corresponding rocket will feature two five-stage boosters, four RS-25 engines and two J-2X engines, more closely resembling the giant Saturn V of the 1960s and 1970s, which was 110 meters high.

The booster’s prime contractor, Orbital ATK, was formed by the merger of Orbital Sciences and erstwhile prime contractor ATK (Alliant Techsystems) on February 9 this year. Orbital itself hit a rough patch in October 2014 when its flagship Antares rocket exploded seconds after taking off from a launchpad in Virginia. It was carrying supplies for a resupply mission to the International Space Station. Wednesday’s test-fire will be Orbital ATK’s first ‘mission’ as a merged company.

Both Orbital ATK and Boeing – the contractor for the SLS’s core module which carry cryogenic liquid hydrogen and liquid oxygen – have reused many features and parts from the erstwhile Space Shuttle program, helping cut costs. Ironically, however, the SLS boosters which contain parts from 23 different Space Shuttle missions across 25 years are not reusable.

NASA will broadcast the test live on its television channel, NASA TV. The event is sure to revitalize public support for an agency that seems long past its golden days, yet whose heritage and legacy are important for the USA to recapture its former foothold in space exploration.

At the same time, whether even a successful test-fire will bode well in the eyes of Congressmen is hard to say: the first SLS test-flight was originally planned for 2017, and now it’s 2018. The size of the program also makes it especially susceptible to changing political winds, as a result of requiring constant and substantial funding to be kept alive.

Making matters worse is, despite motoring along with the development of the SLS itself, NASA hasn’t yet said where it will actually go besides Mars.

Featured image: Artist concept of NASA’s Space Launch System (SLS) 70-metric-ton configuration launching to space. Credit: NASA/MSFC

A voyager on an unknown sea

Early 2012. The Voyager 1 space-probe is millions of kilometres beyond the orbit of the dwarf planet Pluto. In fact, it’s in a region of space filled with scattered rocks and constantly perturbed by charged particles streaming in from outer space. Has it left the Solar System, then? Nobody is sure.

Late 2012. Scientists still aren’t sure if Voyager 1 has crossed over into the interstellar medium. The ISM is the region of the universe between stars, where the probe would definitely have been outside the Solar System. The probe’s batteries had been low for a while. An important instrument on-board that could’ve ‘sniffed’ at the charged particles and known where the probe was is dead. Only something like luck could save the day.

June 2013. Three papers published in Science discuss changes in the magnetic fields around the probe. Some measurements indicate Voyager 1 is in the ISM. Others say it’s just entered a new region of space, a ‘transition zone’ between the Solar System’s outermost fringes and the first tastes of the universe beyond.

August 2013. Luck finally struck. A storm on the surface of the Sun had ejected a massive burst of its own charged particles, way back in March 2012. They coursed in waves throughout the Solar System. When the waves met the charged particles Voyager 1 was swimming in, there was a resonating, a twang in the electromagnetic field. Some other instruments could pick that up well. It was confirmation that Voyager 1 was out and away.

September 2013. The announcement was made to much celebration.

But in December 2014, there was a surprise.

Tsunamis

When the charged particles from the Sun, called a coronal mass ejection, meet the sea of charged particles in the ISM, it’s like a big wave hitting a placid shore. There is a tsunami, a disturbance spreading outward like ripples in water. Scientists don’t know how potent these tsunamis can be, but they assumed not too much because of the distances involved as well as the timescales.

They were wrong. On December 15, NASA reported that Voyager 1 was still recording the effects of a tsunami that had been unleashed 10 months ago, in February. As Don Gurnett, professor of physics at the University of Iowa, noted, “Most people would have thought the interstellar medium would have been smooth and quiet. But these shock waves seem to be more common than we thought.”

Just like a small ball floating on the surface of a pond bobs up and down when ripples pass under it, Voyager 1’s instruments pick up a bobbing of the electromagnetic field around it. These oscillations can be translated to and relayed as a sound with rising and falling pitches. Listen to it here.

One of the telltale signs that Voyager 1 is in interstellar space is that the sea of particles – or plasma – it’s cruising through gets thicker, as if more viscous. Based on observations, the plasma density has been increasing the farther out Voyager 1 goes. “Is that because the interstellar medium is denser as Voyager moves away from the heliosphere, or is it from the shock wave itself? We don’t know yet,” said Ed Stone, project scientist for the Voyager mission at Caltech.

If you’ve listened to the audio file, you’ll see how eerie it feels. The Sun’s coronal mass ejection behaves like a lighthouse in this sense. As its light – in the form of the charged particles – sweeps through space, the little boat called Voyager 1 finds its way in a rough and uncharted sea, one bob at a time. Here’s to the Sun keeping it going.

 

Spitzer has helped choose a near-Earth object the A.R.M. could bring nearer

From its perch up in space, Spitzer can use its heat-sensitive infrared vision to spy asteroids and get better estimates of their sizes.

This is what the author of a study that appeared in Astrophysical Journal Letters on June 19 said in a NASA press release about the space telescope. The Spitzer was used by a group of astronomers that authored the paper to study the dimensions and other physical properties of an asteroid named 2011 MD. They’ve found it to be suitable for NASA’s purpose, i.e. to bring a near-Earth object (NEO) into an orbit around the moon and study it – all by the 2020s. This elevation to suitability also makes 2011 MD the third such candidate NASA will consider as it ramps up the mission, dubbed the Asteroid Redirect Mission (ARM).

This image of asteroid 2011 MD was taken by NASA's Spitzer Space Telescope in Feb. 2014, over a period of 20 hours. The long observation, taken in infrared light, was needed to pick up the faint signature of the small asteroid (center of frame). The Spitzer observations helped narrow down the size of the space rock to roughly 20 feet (6 meters), making it one of a few candidates for NASA's proposed Asteroid Redirect Mission for which sizes are approximately known.
This image of asteroid 2011 MD was taken by NASA’s Spitzer Space Telescope in Feb. 2014, over a period of 20 hours. The long observation, taken in infrared light, was needed to pick up the faint signature of the small asteroid (center of frame). The Spitzer observations helped narrow down the size of the space rock to roughly 20 feet (6 meters), making it one of a few candidates for NASA’s proposed Asteroid Redirect Mission for which sizes are approximately known. Image: NASA/JPL-Caltech/Northern Arizona University/SAO

Why was Spitzer used? From the release:

Prior to the Spitzer study, the size of 2011 MD was only very roughly known. It had been observed in visible light, but an asteroid’s size cannot be determined solely from visible-light measurements. In visible light alone, for example, a white snowball in space could look just as bright as a dark mountain of cosmic rock. The objects may differ in size but reflect the same amount of sunlight, appearing equally bright.

The advantage that infrared light presents, on the other hand, is that it reveals the body’s temperature, mass and density. Subsequently, the study’s authors were able to conclude that 2011 MD is lighter than asteroids usually are, and is possible two-thirds hollow. This, they think, could be because it is actually a collection of rocks or is one rock surrounded by debris. One more thing about this new candidate for ARM is its odd, oblong shape.

The team says the small asteroids probably formed as a result of collisions between larger asteroids, but they do not understand how their unusual structures could have come about. They plan to use Spitzer in the future to study more of the tiny asteroids, both as possible targets for asteroid space missions, and for a better understanding of the many asteroid denizens making up our solar system.

Knowing the size of the NEO to bring closer is important because it will help NASA plan the “how” of the mission. In another press release yesterday, the space agency said it was awarding $4.9 million to 18 proposals each of which described a method to execute the ARM, over a period of six months. NASA started accepting these proposals in March this year and reportedly received 108. Two names quickly jump out from among the proposals:

  • Deep Space Industries, which announced in January 2013 that it plans to scout for a near-Earth object, mine a small sample from it, and return that to Earth by 2016. The press release states that, through the ARM, DSI wants to “examine public-private partnership approaches”.
  • Planetary Society, which wants to put bacteria on the asteroid retrieval vehicle to “transport extremophiles through deep space and return them to Earth to test panspermia and astrobiology.”

The 2011 MD press release is available here, and the one about the proposals, here.